Currently, pseudo-white light-emitting diodes (LEDs) are commonly used as a light source for backlights in liquid crystal display devices. In pseudo-white LEDs, LEDs that emit blue light are used in combination with a yellow phosphor that emits yellow light when excited by the blue light, thereby making it possible to emit white light (consequently, these are sometimes referred to as blue-yellow pseudo-white LEDs). Pseudo-white LEDs offer excellent performance in terms of luminous efficacy and cost.
Patent Document 1 discloses a technology for displaying significantly brighter images on a liquid crystal display device that includes pseudo-white LEDs. Patent Document 1 describes how using pseudo-white LEDs that have a prescribed emission spectrum in combination with color filters that have prescribed spectral transmission characteristics makes it possible to increase the brightness of the white display state without changing the chromaticity coordinates of the white display state.